Diet and coronary heart disease

Area of Science:

• Nutritional Science
• Cardiovascular Disease Epidemiology
• Metabolic Health

Background:

• Dietary saturated fatty acids (SFA) show a moderate correlation with coronary heart disease (CHD) risk across populations, but less so within specific cultural groups or individuals.
• Other dietary factors including total energy, essential fatty acids (EFA), fiber, alcohol, and salt also influence the diet-CHD relationship.
• SFA primarily impacts CHD by disrupting lipoprotein metabolism, increasing low-density lipoproteins (LDL), and affecting cholesterol ester balance in arterial walls.

Purpose of the Study:

• To investigate the role of dietary fatty acids, particularly saturated and polyunsaturated fatty acids (PUFA), in the development of coronary heart disease (CHD).
• To evaluate the impact of dietary interventions, specifically increasing PUFA intake, on serum cholesterol levels and cardiovascular disease incidence.
• To assess the potential risks associated with lowering cholesterol, including non-cardiovascular mortality.

Main Methods:

• Analysis of population-level correlations between dietary saturated fatty acids and CHD incidence.
• Review of two large primary prevention trials involving diets enriched with PUFA.
• Evaluation of findings in conjunction with data from drug-based primary prevention trials.

Main Results:

• Polyunsaturated fatty acids (PUFA) favorably alter lipoprotein metabolism and can substitute for saturated fatty acids (SFA).
• Diets enriched with PUFA reduced serum cholesterol by 10-15% and decreased the incidence of cardiovascular diseases, particularly non-fatal myocardial infarction.
• Both PUFA-enriched diet trials observed an increase in non-cardiovascular mortality, raising concerns about long-term effects.

Conclusions:

• Reducing plasma cholesterol to approximately 210 mg/dl is a reasonable target for communities with high CHD incidence.
• Dietary modifications including reducing fat intake to ≤35% of energy (with SFA at ~10%), increasing fiber, and moderating alcohol consumption are recommended.
• The potential adverse effects of long-term cholesterol reduction on cellular function require further investigation.